Some valuable studies have been done in the aspects of numerical simulation of natural infinite foundation and seismic wave input. The thesis comments the advantages and disadvantages of infinite element

and expatiates on the theory system of ABAQUS infinite element which is improved. The artificial boundary of ABAQUS dynamic infinite element considering the impact of outland fluctuations is proposed. Based on the equivalent boundary force superposition principle

the incident and scattered waves are dealt with separately

and assumed that they are independently to each other. The input ground motion is converted to equivalent stress acting on the interface between the finite element and infinite element to solve the problem of exogenous incident wave. Case study results show that: for the calculation results obtained from inside vibration source and the fixed boundary

the distortion and disturbances appear; the results calculated by the method mentioned above are compared with the results of viscoelastic boundary

which make it certain that the filter function of outgoing scattered wave with the method mentioned above is better than viscoelastic boundary. Therefore

the improved ABAQUS dynamic infinite element boundary method is effective and has certain stability.